Fluid grinding mill with interchange-able liners



Jan. 18, 1966 c. M. TROST 3,229,918

FLUID GRINDING MILL WITH INTERCHANGEABLE LINERS Filed June 5, 1965 3 Sheets-Sheet 1 m w/m I 5 in Z t d 67 INVENTOR.

CON/PAD M. T9087 WWW zm/zzgw ATTORNEYS Jan. 18, 1966 c. M. TROST 3,229,913

FLUID GRINDING MILL WITH INTERCHANG'EABLE LINERS Filed June 5, 1963 3 Sheets-Sheet 2 INVENTOR.

CONRAD M TRUST ATTORNEYS iymzmzw Jan. 18, 1966 c. M. TROST 3,229,913

FLUID GRINDING MILL WITH INTERCHANGEABLE LINERS Filed June 5, 1963 s SheetsSheet 5 r u I 98 1 I M INVENTOR.

CONRAD M TROST ZW%M A TTOIQNEVS United States Patent C) 3,229,918 FLUID GRINDING MILL WITH INTERCHANGE- ABLE LINERS Conrad M. Trust, Moorestown, N.J.; Eva Wrlhelmme Trost, executrix of said Conrad M. Trost, deceased, assignor to Helme Products, Inc., a corporation of New Jersey Filed June 5, 1963, Ser. No. 285,682 Claims. (Cl. 241-39) This invention relates to comminuting mills and particularly to a type thereof which is energized by a pressure fluid, which has no moving mechanical parts, which is adapted to the handling of extremely small quantities of material to be ground and wherein the entire internal surfacing thereof can be readily changed as needed to accommodate the mill to the handling of materials of a variety of different types.

While fluid grinding mills have been known for a number of years and have appeared in a wide variety of different shapes and sizes, they have normally been limited in their use to handling on a continuous basis very large quantities of .a single material. Under these circumstances, it has previously been known to line the mill with a material chemically inert with respect to, and mechanically capable of resisting abrasion by, the material to be ground. However, such lining has in the past been of a substantially permanent nature so that a given mill has been limited in its use to materials which are mechanically and chemically substantially unaffected by the lining, or other internal surfacing, of the mill, at least within the limits imposed by the use to which the said material is to be put.

This has accordingly in the past left unfilled a Wide area of potential use of mills of this type where only small quantities of a given material are to be ground at a given time and, more importantly, where the material being ground is changed from time to time wherein successive materials differ widely from each other in both their chemical and physical respects.

Therefore, the objects of the invention include:

(1) To provide a comminuting mill utilizing pressure fluid as the grinding medium which is primarily adapted for handling a succession of diflerent materials, said materials having widely varying chemical and/or physical properties.-

(2) To provide a comminuting mill, as aforesaid, wherein all surfaces contacted by either the grinding fluid or the material being ground are covered by a lining material selected as needed to be both chemically and physically resistant to attack by the material handled in the mill.

(3) To provide a comminuting mill, as aforesaid, wherein, all parts exposed to either the grinding fluid or the material being handled can be protected by suitable liners and wherein said liners can be readily and quickly changed.

(4) To provide a comminuting mill, as aforesaid, capable of handling very small quantities of material to be ground, including quantities in the order of one to three grams, or more as desired.

(5) To provide a comminuting mill, as aforesaid, following the general organization and pattern of previously known mills whereby operators thereof will be capable of operating a mill meeting the foregoing objects enumerated herein on the basis of their experience with previous mills of this general type and without special training.

(6) To provide a mill, as aforesaid, which will constitute only a relatively simple modification of previously known mills of this general type whereby same may be manufactured and its operation reasonably predicted on the basis of technology and knowledge relating to such previously known mills.

(7) To provide a mill, as aforesaid, which will be sufficiently simple mechanically as to be capable of manufacture without excessive cost.

(8) To provide a mill, as aforesaid, which will be sufficiently simple as to be capable of manufacture from a variety of materials highly resistant .to both mechanical and chemical attack without excessive cost.

(9) To provide a mill, as aforesaid, which will be capable of effective operation over a long period of time with a minimum of maintenance, effort and expense.

Other objects and purposes of the invention will be apparent to persons acquainted with apparatusof this general type upon reading the following specification and inspection of the accompanying drawings.

In the drawings:

FIGURE 1 is a broken, front elevational view of a device embodying the invention with the front cover plate removed and showing parts thereof aligned with the grinding recess in central cross section.

FIGURE 2 is a sectional view essentially as taken on the line II-Il of FIGURE 1.

FIGURE 3 is a left-side elevational view of the device of FIGURE 1.

FIGURE 4 is a front elevational view of the body member of the device of FIGURE 1.

FIGURE 5 is a partially broken, right-side elevational view of the body member of FIGURE 4.

FIGURE 6 is an elevational view of the left retainer plate as seen from the left side of FIGURE 1.

FIGURE 7 is a front elevational view of an air-flow deflector included in the device of FIGURE 1.

FIGURE 8 is a left-side elevational view of the deflector of FIGURE 7.

FIGURE 9 is a front elevational view of the cover plate for the device of FIGURE 1.

FIGURE 10 is an exploded isometric view of the liners employed in the device of FIGURE 1.

FIGURE 11 is a fragmentary front elevational view similar to FIGURE 1 but showing a modified material feeding arrangement.

For convenience in description, the terms upper, lower, left, right, front and rear will have reference to the mill and parts thereof as appearing in FIGURE 1. The terms inwardly and outwardly will have reference to the geometric center of the mill and parts thereof. The above terms together with derivatives and words of similar import will be used in the following description for convenience in reference only and not as limiting.

General description The objects and purposes of the invention, including those set forth above, have been met by providing a fluid grinding mill comprising a body member having a constant depth classification recess in the front face thereof and having a grinding recess communicating with said classification recess along one side thereof. Means are provided for introducing a removing fluid and comminuta-ble material to the mill. Liners are provided for covering surfaces of said recesses that would otherwise be exposed to fluid-entrained material and for channeling and controlling such fluid. The liners are held firmly in place by a cover plate and a pair of end retainer plates whereby such liners are easily removed for replacement with others of diflering physical and chemical characteristics whereby the mill can be used to grind a wide variety of different materials with a minimum of down time.

Detailed description The fluid grinding mill 10 embodying the invention includes a preferably rigid and monolithic body member 11 (FIGURES 4 and 5) having a planar front face 12 including a classification recess 13 in the upper portion thereof. The classification recess 13 has aplanar rear wall 16 which is parallel to the front face 12 of the body member 11 and has a peripheral wall 17 extending perpendicularly forwardly from the rear wall 16. Thus, the classification recess 13 has a constant cross-sectional configuration from the front to the rear thereof. The peripheral wall 17 of the classification recess 13 is es sentially horseshoe shaped preferably having a rounded upper portion connecting a pair of generally downwardly extending legs.

A circular outlet recess 23 is provided in the upper portion of the rear wall 16 and has coaxial therewith an outlet opening 29 through the rear of the body member 11.

In the particular embodiment shown in the drawings, the upper portion of the peripheral wall 17 describes a semicircle and the lower legs of said peripheral wall are straight and tangential with and convergent away from said upper portion. Further, the outlet opening 29 is coaxial with said semicircular upper portion.

The body member 11 has a grinding recess or groove 21 in the forward face thereof and opening through the side walls thereof. The groove 21 has a rectangular cross section which is constant throughout its length whereby the top and bottom walls 22 and 23 thereof are parallel to each other and are perpendicular to the forward face 12 of the body member 11 and whereby the rear wall of said groove 21 is parallel to the face 12. Intermediate its ends, the groove 21 communicates at its upper side with the lowermost extent of the classification recess 13. The rearward depth of the groove 21 is preferably slightly greater than the rearward depth of the classification recess 13 whereby a portion 26 of the upper Wall 22 of the groove 21 separates the rear wall 24 thereof from the rear wall 16 of the classification recess 13.

Referring to FIGURES l and 2, a bushing 31 is coaxial with and extends the length of the outlet opening 29 and has a flanged end seated against the recess 28. The

bushing 31 has a full bushing liner 32 internally fitted therewithin and extending the length thereof. The forward faces of the bushing 31 and bushing liner 32 are preferably coplanar with the rearward wall 16 of the classification recess.13.

A rear liner plate 34 is removably seated against the rear wall 16 and its peripheral edge is closely adjacent the peripheral wall 17 of the classification recess 13. The rear liner plate 34 has a hole 35 therethrongh communicating with the passage defined 'by the bushing liner 32. The lower edge of the rear liner plate 34 is coplanar with the upper wall 22 of the groove 21 in the body member 11.

The rear liner plate 34 is held against rearward and sideward movement withinthe classification recess 13 by teh configuration of the body member 11. Aquaripheral linear band 36 has forward and rearward faces parallel with the forward face 12 of the body member 11 and with the forward face of the rear liner plate 34 and has an outer peripheral wall perpendicular to its forward and rearward faces. The peripheral liner band 36, when installed, continuously but removably contacts the forward face of the rear liner plate 34 and its outer peripheral wall is substantially in continuous but removable contact with the peripheral wall 17 of the classification recess 13. Thus, the peripheral liner band, when installed in the body member 11, is essentially horseshoe shaped and its lower ends are preferably coplanar with the uppper wall 22 of the groove 21.

An essentially trapezodially shaped deflector 38, having parallel forward and rearward faces and a rearward thickness equal to that of the peripheral liner band 36, is secured to the forward face of the rear liner plate 34 by any convenient means such as the screws 41. When so installed, the deflector 38 has a bottom wall 00- planar with the bot-tom edge of the rear liner plate: 34,

side walls adjacent to but spaced from the lower legs of the peripheral liner band 36 and an upper face spaced downwardly from the opening 35 in the rear liner plate 34.

The forward [faces of the peripheral liner band 36 and deflector 38 are preferably coplanar and spaced rearwardly from the front face 12 of the body member 11..

A forward liner plate 42 is preferably identical to the rear liner plate 34 with the omission of the hole 35.

a return leg passage 47 on the left and right sides, re-.

spectively (FIGURE 1), of said deflector.

A plurality of grinding recess or groove liners are disposed in axially contacting relationship to one another within and through the length of the groove 21..

The external cross-sectional configuration and size of the groove liners is identical to that of the groove 21 whereby the front faces of the groove liners are coplanar with the front face 12 of the body member 11.

Referring to FIGURE 1, the leftwardmost groove liner or venturi block 49 extends rightwardly from the leftward end of the groove 21 and has a central opening or venturi 51 therethrough running the length thereof. The central opening 51 is preferably provided with a divergent leftward end. A second groove liner or impact chamber liner. 53 comprises a lower, upwardly opening U- shaped member 54 partially covered by a cap 55 whereby the impact chamber 56 defined thereby communicates with the central opening 51 in the block 49 and communicates with the otftake leg 46 of the classification chamber 44. A third groove liner or guide block 58 extends rightwardly from the impact chamber liner 53 and is located below the bottom edge of the deflector 38 above described. The guide block 58 has a central opening 59 therethrongh which preferably has a somewhat diverging rightward end. A fourth groove liner or return chamber liner 61 extends rightwardly from the guide block 58 and has a relatively deep central groove or return chamber 62 therein along the axis thereof which opens upwardly into the return leg 47 of the classification chamber 44 and also communicateswith the central opening 59.- The fifth groove liner 64 extends rightwardly from the return chamber liner and has a central opening 66 arranged longitudinally thereof and in communication between said return chamber 62 and the right-hand end of said fifth groove liner.

The fifth liner has a right-hand portion extending beyond the groove 21 which is of circular cross section for receiving thereon a suitable collar 68 which is fixed to the right side of body member 11 by screws 69. The collar 68 restrains the above-described series of groove liners from moving rightwardly out of the groove 21. A leftward retaining plate 71 is secured to the leftward side of the body member 11 by means of screws 72 for restraining the above-described groove liners against movement out of the leftward end of the groove 21. The left retainer plate 71 has secured thereto, by any convenient means such as welding, a generally cylindrical adapteraxial with the central opening 51 of the first groove liner 49 hereinabove discussed. The material to be ground vis placed in the hopper 74, the interior of which communicates with the opening 76. Nozzles 78 and 79, which may be and are here shown as being identical, are respectively adjustably secured within the adapter 73 and the fifth liner 64 by means of set screws 81 and 82, respectively. The nozzles 78 and 79 are positioned so that their small diameter outlet ends are aimed into the central opening 51 and return chamber 62, respectively. The outer ends of the nozzles 78 and 79 are connected to any convenient source of pressure fluid, such as compressed air as by conventional hose connections.

The aforementioned liners in the grinding and classification recesses are held against forward movement by a front cover plate 84 (FIGURES 2 and 3) which is secured to the front face 12 of the body member 11 by a plurality of screws 86. A gasket 87 may be employed between the front cover 84 and the remainder of the mill to provide an air seal. Further gaskets 88 and 89 may be employed at the ends of the groove 21.

The material from which the aforementioned liners are made will depend upon the characteristics of the material to be ground. In a particular case, however, said liners were made from Teflon. In another situation, and as shown in the drawings, the front liner plate and front cover were made of clear Plexiglas and the gasket 87 was provided with a hole through the center thereof for allowing the front liner plate 42 to contact the front cover 84 whereby the interior of the mill was visible when assembled. Thus, the grinding action of the mill could be observed visually by the operator.

Operation The operation of the mill unit above described is similar basically to that of Patent No. 2,735,626 inasmuch as pressure fluid hereinafter assumed to be air for descriptive purposes, flowing into the leftward or secondary nozzle 78 aspirates materials to be ground from the hopper 74 and carries same through the central opening 51 of the block 49 into the impact chamber 56. Simultaneously, a blast of air from the rightward or primary nozzle 79 flows through the return chamber 62 and central opening 59 in the guide block 58 to enter the impact chamber 56 directly opposite the first described or secondary blast of air. The interaction of these two thin pencils of air impinging from opposite directions upon each other causes the particles carried in the secondary stream to be eroded and further causes the combination of the air stream and particles to travel upwardly into the offtake leg 46. The left side of the deflector 38 tends to throw particles which strike it toward the liner band 36 defining the radially outer edge of the classification chamber 44. The air stream then travels around the perimeter of the classification chamber 44, the heavier particles therein being forced by centrifugal force to the outside of the chamber and the finer particles, less affected by centrifugal force, tend to move toward the center of the classification chamber 44. Continued movement causes the heavier particles to move downwardly into the down leg 47 and into the return chamber 62 whereas the lighter particles and entraining air continue to circle the outlet defined by the opening 35 and bushing liner 32 until they move with that portion of the air exiting through the opening 35 outwardly therethrough and into suitable receiving means, not shown.

The heavy particles returned to the return chamber 62 are aspirated by the air primary jet from the rightward nozzle 79 whereby same are forced through the opening 59 in the guide block 58 to impinge as a narrow stream of particles upon a similar stream of new particles entering, as above described, from the hopper 74 through the passage 51 and into the impact chamber 56. A high incidence of collisions between the particles in the opposing primary and secondary air streams occurs and causes comrninution thereof. Again the resulting particles are pushed upwardly into the leg 46 of the classification chamber 44 and the cycle repeats.

The nozzles 78 and 79 can be adjusted axially of the groove 21 for giving the correct aspirating action.

The instant invention differs from previous practice, however, in that the classification chamber 44 and the various passages subjected to the presence of particles to be ground are defined by removable and interchangeable liners. Thus, liners of different material may be substituted when desired and the various openings and chambers may all be varied in size and shape and as desired simply by removing and replacing the liners defining same.

Modification Referring now to FIGURE 11, a modified feeding apparatus is shown. Parts thereof shared with the abovedescribed embodiment are designated with the same reference numerals with the sufix a added thereto and such parts need not be further described.

A modified adapter replaces the adapter 73 of FIG- URE 1 and has a short length of rigid tubing 94 secured, by any convenient means such as welding, to the rightward end thereof in place of the hopper 74 (FIGURE 1) and communicating with the central opening therein. A pipette 91 is attached by means of a suitable piece of flexible tubing 92 to the free end of the tube 94. The location of the nozzle 78a is adjusted within the adapter 90 so that the pressure within the tubing 92 falls whereby material from a source 93 is drawn into the pipette, through the tube 92 and propelled by the secondary air stream through the remainder of the mill as described hereinabove in connection with the preferred embodiment of the invention.

Although a particular preferred embodiment of the invention has been disclosed hereinabove for purposes of illustration, variations or modifications thereof lying within the scope of the appended claims, are fully contemplated.

What is claimed is:

1. A grinding mill of the fluid jet type comprising a body member having a planar front face and being formed with a classification recess extending inwardly from the front face and having a rear wall extending parallel to the front face and peripheral walls extending substantially perpendicular thereto, the body member also being formed with a grinding recess extending inwardly from the front face and providing a passageway extending laterally through the body member, the grinding recess being in communication with the classification recess along one side thereof and having a rear wall extending substantially parallel to the front face and side walls substantially perpendicular thereto, a cover member mounted on the planar front face of the body member to cover the recesses formed therein, and liner means comprising a plurality of liner members which are physically and chemically resistant to attack by the material to be ground mounted within the recesses so as to cover the surfaces thereof.

2. A grinding mill according to claim 1 wherein the liner means comprises a substantially flat liner member mounted against the rear wall of the classification recess, a liner member of substantially rectangular cross-section mounted against the peripheral walls of the classification recess, a substantially flat liner member mounted on the cover member to engage the side of the rectangular crosssection member, and a plurlaity of liner members of rectangular cross-section mounted with the grinding recess.

3. A grinding mill according to claim 2 wherein one of the plurality of liner members mounted within the grinding recess comprises a member having an internal impact chamber and a lateral opening communicating with the classification recess.

4. A lgrinding mill according to claim 2 wherein the liner members within the recesses of the body members are removably inserted therein and the liner member mounted on the cover member engages the rectangular 7 cross-section liner member within the recess to refain 2,690,880 the liner members in position therein. 2,704,635 5. A grinding mill according to claim 1 wherein the 2,735,626 grinding recess is deeper than the classification recess. 2,958,472 5 3,158,331

References Cited by the Examiner UNITED STATES PATENTS 5/ 1952 Trost et a1 24139 Chatelain 241-39 Trost 241--5 Trost 241-39 Erickson; 241-39 I Wilson et a1 241--21 X Examiners. 

1. A GRINDING MILL OF THE FLUID JET TYPE COMPRISING A BODY MEMBER HAVING A PLANAR FRONT FACE AND BEING FORMED WITH A CLASSIFICATION RECESS EXTENDING INWARDLY FROM THE FRONT FACE AND HAVING A REAR WALL EXTENDING PARALLEL TO THE FRONT FACE AND PERIPHERAL WALLS EXTENDING SUBSTANTIALLY PERPENDICULAR THERETO, THE BODY MEMBER ALSO BEING FORMED WITH A GRINDING RECESS EXTENDING INWARDLY FROM THE FRONT FACE AND PROVIDING A PASSAGEWAY EXTENDING LATERALLY THROUGH THE BODY MEMBER, THE GRINDING RECESS BEING IN COMMUNICATION WITH THE CLASSIFICATION RECESS ALONG ONE SIDE THEREOF AND HAVING A REAR WALL EXTENDING SUBSTANTIALLY PARALLEL TO THE FRONT FACE AND SIDE WALLS SUBSTANTIALLY PERPENDICULAR THERETO, A COVER MEMBER MOUNTED ON THE PLANAR FRONT FACE OF THE BODY MEMBER TO COVER THE RECESSED FORMED THEREIN, AND LINER MEANS COMPRISING A PLURALITY OF LINER MEMBERS WHICH ARE PHYSICALLY AND CHEMICALLY RESISTANT TO ATTACK BY THE MATERIAL TO BE GROUND MOUNTED WITH THE RECESSES SO AS TO COVER THE SURFACES THEREOF. 